Avalanche Danger Scale

The Mount Washington Avalanche Center (MWAC) began using a revised avalanche danger scale for the 2010/11 season. The system was designed with input from avalanche professionals across the United States and Canada and is now being adopted by nations as far away as New Zealand. The revised scale reduces some of the ambiguity of the previous scale, incorporates risk by referring to typical avalanche sizes expected, and provides more definitive travel advice for backcountry recreationists.

“It was especially encouraging to work closely with our Canadian colleagues to come up with a unified scale. This will only help in our efforts to promote avalanche forecasting consistency and to improve safety for the many people who recreate in the backcountry in both countries” according to Karl Birkeland, the U.S. lead on the project and an Avalanche Scientist with the USDA Forest Service National Avalanche Center. The closest Canadian avalanche center is located a full day’s drive from Mount Washington in eastern Quebec’s Chic Choc Mountains on the Gaspé Peninsula.

“For those familiar with the system that has been used in recent years the new avalanche danger scale will be easy to understand” says Justin Preisendorfer, USDA Forest Service Snow Ranger at the MWAC. For those who are just venturing into recreation in steep snow-covered terrain, Preisendorfer suggests familiarizing themselves with the definitions and travel advice that are associated with each of the system’s five danger levels. “Do a little reading ahead of time and then get yourself enrolled in an avalanche course” he says. “It’s the best investment that you can make if you want to have safe winter adventures in any mountain range, the White Mountains included.” Check the website www.mountwashingtonavalanchecenter.org for a list of local avalanche course providers as well as a detailed summary of the changes to the danger scale including descriptions of the five danger levels.